Dissolver and shifter for optical systems



Oct. 10, 1933. H OWENS I 1,929,988

DISSOLVER AND SHIFTER FOR OPTICAL SYSTEMS Filed May 3, 1929 IN VEN TOR.

A TTORNEY Patented bot. 10,1933

mssonvs Application May 3, 1929. Serial No. 360,247 7 9 Claims. 31.179-1003 '1 This invention relates to improvements in dis- 'solversandshifters for optical systems, and more particularly for optical systemssuch as are used for recording and reproducing photographic soundrecords, the principal object of the invenjtion being to provide adevice of this character whereby the position of the light focused upona film traveling past the optical system with relation to the width of asound record on said film can be readily controlled.

A further object of the invention-is to provide a simple and efiioientmeans for gradually varying the length of the eifective portion of theslit through which light passes to the film, thereby to produce adiminuendo or crescendo effect of the reproduced sound record carried bythe film.

Other objects and adva'ntagesof the invention will appear as thedescription proceeds.

In the drawing accompanying this specification,

Figure 1 is a longitudinal sectional view through {an assembled opticalsystem' embodying the features of the present invention;

Figure 2 is a broken away longitudinal sec,- tional view illustrating ona larger scale the construction and relative disposition ofthe'dissolver and shifter. c

Figure 3 is an end view of the dissolver and shifter assembly andillustrating the means for operating these members;

Figure 4 is a sectional plan view through the ousing of the shifter anddissolver, taken at rightangles to Figure 2; and 1 Figures 5 and 6 areplan views illustrating developments of the drums forming the shifterand dissolver respectively.

The same characters of reference designate the same parts in thedifferent figures of the draw- In the art of reproducing photographicsound records it is well known that a beam of light is focused upon anarrow slit, the areal image of which is focused upon the sound track orrecord on the film as it moves past said'beam. The rays passing throughsuch sound record are of course modulated thereby and the modulated raysare then translated into electric'impulses by a suitable light sensitiveelement, such'as a photo electric cell, which impulses are thenamplified and rendered audible by a loud speaker device. Inasmuch as thefilm moving mechanism and the reproducing units are well known and maybe of any of a number of types and kinds, it has not been deemednecessary to ShOW them in connection with my improved shifter anddissolver,

which is useful in connection therewith.

It will be understood also that myinvention is 7 equally well adaptedfor use with a photographic sound recording means. limited therefore totheparticular combination 0 use to which my invention is put. I

Referring to the drawing, 1, 1a designate a twopart tube, thepartshaving a threaded and shouldered connection as indioatedat 1b inFigure 1.

Within the tube is suitably mountedan optical system comprising acondenser lens assemblyv 2 and a focusing lens assembly 3, and betweensaid lens assemblies is disposed within the tube'l anv exteriorlycylindrical member 4 having a. longi-'.

tuclinally extending opening 5 preferablyof rectangular form, saidmember being secured in .the tube 1v by means of set screws 6. Withinthe opening 5 is disposed an exteriorly rectangular block '7, said blockbeing secured against move-f ment by means of a set screw 8 passingthrough the wall-of the member 4 and into the block. The

block '7 is bored longitudinally, and on the. end

thereof nearest the condenser lens are secured by means of screwso apair of plates 10 and 11'5 forming between them the usual narrow slit 12through which the light .rays are projected by the condensing lenstoward the focusing lens.

The block lis also bored transversely thereof,:

said transverse bore being in communication with the slit 12 formedbetween the plates 10 and 11, and within thistransverse bore aredisposedthe members about to be described and which I have 'termed hereinrespectively a shifter and a dis- I do not wish to be extension 15 whichis mounted for rotation in the other end wall of the block 7, said drumbeing disposed so as to rotate immediately adjacentto the slit 12. Inthe body of the drum is formed an opening lfigextending obliquely acrossthe drum, said opening merging at one end into an opening 17 extendingin the direction of rotation of the drum. The form of these openings isshown best in Figure 6. The extension 15 is provided at its cuter freeend with a knob orbutton-18for manually rotating the drum. By reason ofthis construction it will readily'be seen that with the drum disposedadjacent to the slit 12, light will pass through only that portion ofthe length of the slit which-is not covered by the drum, in

465 :inshown and described.

tion of the length of said slit, at one end thereof, 1i

.e-ablysalso'"witha'leveri22. The drum 19 Ihave.

.atermedtherein the dissolver; since its function is "sof aanyalight.:Tothis end, the drum l9 rotates within the drumclSinlcloseicontact'therewith, -aand==as shownherein. is providediwith anapproxis Imately v+shaped opening '23, from which: it will s80. be:obvious that when the drum 19 "is 1 in such position thatutheWidestLpart of itheopening 23 i coincides with the "slit 1'27. and thatportion of the openingr lfi in :drum 13' which'happens tobe in :line'swithsaid-slit, light will pass through the -.sslit forthe'f-ull'widthot the opening 23. If-now .the'iknob' fll. isrotatedsons: to carrythe apex of 1:;th6iVftOWfiId the-slit, it isobvious thatthe length moi theiportion of the=slitthrough which the light passeswill :be gradually diminished and finally aentirely .closed; thisproducing the diminuendo rt'orcgradually"softening effects-which are sodesssirable in the :sound reproduction. it will "be imiiderstood;ofcourse, that the form of the openin the drums will be determined bythe effect -which it is desiredtoproduce. For instance, if finstead ofstarting with full volume andgra'd- 'uallyrdecreasing to,- nothing, orvi'ce"versa,i whioh ,emay e be accomplished 'by rotating the drum 19iinathe opposite direction, it is desired to -start iverysoftly; then=increasetto .full volume and then .ngain reduce toin'othing :this mightbe accomiplished'by; providing a diamond shaped opening linsteiadr of a1V as illustrated. And "so, for 1 any hfiect whichitimay bezdesiretl-toobtain theiprovision of the proper combination of openings iwill..accomplish=.the desiredresult; It wvill=be under- ;;stood, oficourse,that-the size of thew-idest 'p'on ,ttionaof theopening, 231will bedetermined accord- :to f the length of the slit r used: and the width=or disposition of :thezphotographic soundrecords onthe'filmipassingsaid slit.-

1.11; should be noted also that'thepperation'zof :the shifter: andl'di-ssolver drums may be I autoematically controlled insteadofinanually ashere- :-I- claim: 7 v :1.,;In"an' optical systemfforphotographicsound .t-recording and reproducing including, i lightipro-..-3'ect,ing;means,:-means:having a fixed narrow slit #7 in the;path.-ofprojection, and rotatably adjust- .able :means ,having an opening. sodisposed asto :yary,:upon rotation the position of tltaelightipasvesagethrough said slit relatively to the length of :the:s lit. r

2. In-an optical system forsphotographic sound tolgradually close: theslit" 12 against the passage recording and reproducing including, lightprojecting means, means having a fixed narrow slit in the path ofprojection, rotatable adjustable means having an opening so disposed asto vary upon rotation the position of the light passage through saidslit relatively to the length of the slit, and means adjustablerelatively to said slit *andto rotatble means to vary'the' 'Width of thelight passagethrough the slit.

3. In an optical system for photographic sound recording and reproducingincluding, light projecting means, means having a fixed narrow slitinthe path of projecting, and a rotatable mema ber havinga' portionprovided with an opening "movable across said slit upon rotation of saidmember -for varying the position of the light passage through the slitrelatively to the length of said slit.

4. ln anoptical system for photographic sound recording and reproducingincluding light proj ecting'irneans, means having a fixed-narrow slitthe path-ofprojection,' and a rotatablemember having a portion providedwith' 'an opening movablecacrosssaidslit upon rotation-of said memberfor varying the position of 'the" light 'ipassage throughthe'slitrelatively to the-length of said slit; and a second membermovable across usaidslit and having a v=shaped -op'enir'ig for varyingthe width of the light'pa'ssage through the slit. 105

5mm" an optical system for-photographic sound recording and reproducingincluding, light proijectingmeans, means' 'havingf a slit i'n the pathbiz-projection, 'a member disposed a'djacent to said 1slit and". mountedfor rotation a cross the 'longillfi wtu'dinal axis ofithe s1it,1saidmember having-an "ripening therein adaptedto registerlwith-varyingportions ofthe' length of zthe' slit according t'o the adjusted positionofsaid member, and means for rotating said member.

6.. In an' optical system; lightprojectingmeans, means having wslit in'the path of projection, a member disposed i-adjacent'to said slit "andmounted for rotation-across thelongitudinalaxis I ofr-the' slit; and'means for rotating saidrriember,' 20 I'Sflid member having an openingextending obliquely to the longitudinal axis of thesIltWhereby uuponfotationbf said member its opening'will "-registerwith 'varyingiportions of the length or the slit. v 225 7..1-'In='an opticalsystem,1ight. projecting means, means having aYslit in ther'path ofprojection,"a member disposed adjacent to "said slit and mountedforrotation across the longitudinal axis of the 'slitand means forrotatingsaidmemberfimt) said member having an opening extendingobliquely to the :longitudinal axis of :the slit, 'and merging into anopening e'xtendingin a direction at right angles to said longitudinalaxis, said right angular opening being adapted-to register with a ji35predetermined portion of the length of the slit and'said oblique openingbeing adapted toregister with varying portions of saidslitaccording tothe angulariposition of the rotatable member. H

8. In an optical system foriphotographic sound 140 recording andreproducing including, .light projecting means, jmeans having a slit inthe'path of projection, a member disposed for'rotation .acro'ss thelongitudinal axisof said slit, said memher havinganangularopening'therein adapted iT45 tion with said first drum andhaving in its wall an opening adapted to register with the opening insaid first drum, the opening in the second drum being of such form as tovary the widthvof the light passage through the slit and the opening insaid first drum aceording to the angular position of the second drum,and independent means for rotating said drums.

' FREEMAN H. OWENS.

